Sensitive Reaction Research Articles

Metal doping fabricated heterobimetallic nickel-zinc composites and its performance-enhancing sensitivity towards nitrogen dioxide

Monitoring and detecting poisonous nitrogen dioxide (NO2) is greatly challenged by ambiguous knowledge about the sensing mechanism and structures of sensitive materials and reaction intermediates. In particular, synthetic strategies like doping and coupling, although do improve gas-sensing activity, have made the structural identification rather difficult. In the work, we have comprehensively examined nickel-doped zinc oxide (marked as ZON) and its material-coupled composites (ZON/Y) for sensing NO2 by density functional theory. The material (Y) varies from graphitic carbon nitride (CN), graphene (Gr) to cellulose (Cel). It is revealed that the metal doping greatly promotes the NO2 adsorption over the material coupling. This well reproduces the experimental findings that the Ni-doped ZnO has much faster response time than ZnO, ZnO/g-C3N4 and ZnO/graphene. Of all the studied SMs, ZON/CN exhibits superior NO2 gas-sensing performance. Along the reaction pathway, it gives NO2 adsorption free energy of − 0.860 eV, followed by the mildest uphill process of catching the second NO2 (0.320 eV) and the modest downhill process of forming nitrate (−0.680 eV). The large adsorption energy of the initial step is attributed to the fabricated heterobimetallic Ni-Zn sensing active sites. The better sensitivity of ZON/CN is further evidenced by analyses of structures and interfacial bondings.

JAK2V617F mutation is highly prevalent in patients with ischemic stroke: a case-control study

AbstractIschemic stroke has a high recurrence rate despite treatment. This underlines the significance of investigating new possible cerebrovascular risk factors, such as the acquired gene mutation JAK2V617F found in 3.1% of the general population. We aimed to investigate the prevalence of the JAK2V617F mutation in a population with ischemic stroke compared with that in matched controls. We enrolled 538 consecutive Danish patients with ischemic stroke (mean age, 69.5 ± 10.9 years; 39.2% female) within 7 days of symptom onset. Using multiple-adjusted conditional logistic regression analysis, we compared the prevalence of JAK2V617F with that in age- and sex-matched controls free of ischemic cerebrovascular disease (ICVD) from the Danish General Suburban Population Study. DNA was analyzed for JAK2V617F mutation using sensitive droplet digital polymerase chain reaction in patients and controls. Of the 538 patients with ischemic stroke, 61 (11.3%) had JAK2V617F mutation. There were no differences in patient demographics or cerebrovascular comorbidities between the patients with and without mutations. Patients with ischemic stroke were more likely to have the JAK2V617F mutation than matched controls, in whom the JAK2V617F prevalence was 4.4% (odds ratio, 2.37; 95% confidence interval, 1.57-3.58; P < .001). A subanalysis stratified by smoking history revealed that the association was strongest in current smokers (odds ratio, 4.78; 95% confidence interval, 2.22-10.28; P < .001). Patients with ischemic stroke were 2.4 times more likely to have the JAK2V617F mutation than matched controls without ICVD when adjusting for other cerebrovascular risk factors. This finding supports JAK2V617F mutation as a novel cerebrovascular risk factor.

Recent Developments on Photochemical Synthesis of 1,n-Dicarbonyls.

1,n-dicarbonyls are one of the most fascinating chemical feedstocks finding abundant usage in the field of pharmaceuticals. Besides, they are utilized in a plethora of synthesis in general synthetic organic chemistry. A number of 'conventional' methods are available for their synthesis, such as the Stetter reaction, Baker-Venkatraman rearrangement, oxidation of vicinal diols, and oxidation of deoxybenzoins, synonymous with unfriendly reagents and conditions. In the last 15 years or so, photocatalysis has taken the world of synthetic organic chemistry by a remarkable renaissance. It is fair to say now that everybody loves the light and photoredox chemistry has opened a new gateway to organic chemists towards milder, more simpler alternatives to the previously available methods, allowing access to many sensitive reactions and products. In this review, we present the readers with the photochemical synthesis of a variety of 1,n-dicarbonyls. Diverse photocatalytic pathways to these fascinating molecules have been discussed, placing special emphasis on the mechanisms, giving the reader an opportunity to find all these significant developments in one place.

Evaluation of rainbow trout (Oncorhynchus mykiss) organotypic intestinal platforms: cellular responses after long-term exposure to in vitro digested feed

Reliable and predictive in vitro models would support the search for new raw materials that can improve current fish diets. We recently developed some rainbow trout (RT) intestinal cell-based organotypic platforms demonstrating that the platform type modulates the degree of cell differentiation achieved in vitro and here we studied whether such differentiation correlates with their response to a prolonged exposure to a diet rich in fish meal. We compared three options, seeding the RTpiMI and RTdiMI cell lines derived respectively from the proximal or the distal intestine on (1) the polyethylene terephthalate (PET) culture inserts ThinCert™ (TC); (2) the TC coated with RT fibroblasts embedded within Matrigel® (MMfb); and (3) the highly porous polystyrene scaffold Alvetex™ also populated with fibroblasts (AV). Platforms have been exposed for 21 days to increasing concentrations of feed pellets digested in vitro by gastric and intestinal RT enzymes (IVD). Cells exposed to culture medium without IVD in each platform were used as controls. TEER values became significantly higher than their respective controls in most culture conditions. At the end of culture, epithelial cells formed multilayers irrespective of cell line or platforms if exposed to IVD, but not in the controls. This proliferative activity followed a dose-dependent pattern in the AV, did not vary in MMfb, and was highly variable in the TC. Moreover, IVD induced the formation of a few goblet-like cells characterized by rounded vacuoles. In parallel, alanine aminopeptidase activity completely disappeared in the MMfb, significantly decreased in the AV, but did not change in TC. These changes suggest a de-differentiation of the enterocytes and their partial differentiation towards the secretory lineages. Overall, the three platforms reacted differently to a pronged exposure to IVD: TC quenched most of the cell responses, MMfb generated overly sensitive reactions, while the AV react mostly in a dose-dependent manner possibly generating more physiological results.

Comparative Analysis of the Immune Response and the Clinical Allergic Reaction to Papain-like Cysteine Proteases from Fig, Kiwifruit, Papaya, Pineapple and Mites in an Italian Population.

Several plant papain-like cysteine proteases are exploited by the food, cosmetic, pharmaceutical and textile industries. However, some of these enzymes can cause allergic reactions. In this context, we investigated the frequency of sensitization and allergic reactions to some fruit and/or latex cysteine proteases, which are used as additives by the food industry to improve and modify the quality of their products. The FABER test was used to analyse the patients' sensitization towards five plants and, for comparison, two homologous mite cysteine proteases. In an Italian population of 341 allergic patients, 133 (39%) had IgE specific for at least one of the seven cysteine proteases under investigation. Most of the patients were IgE positive for Der p 1 and/or Der f 1 (96.38%) reported a clinical history suggestive of respiratory allergy to mites, whereas none of the subjects sensitized to the homologs from papaya, pineapple and fig reported allergy symptoms following ingestion of these foods. Only one patient referred symptoms from ingesting kiwifruit. Therefore, the obtained results showed that sensitization to the fruit enzymes was only rarely concomitant with allergic reactions. These observations, together with the literature reports, suggest that the allergy to plant papain-like cysteine proteases might mainly be an occupational disease.

Tricellulin, α-Catenin and Microfibrillar-Associated Protein 5 Exhibit Concomitantly Altered Immunosignals along with Vascular, Extracellular and Cytoskeletal Elements after Experimental Focal Cerebral Ischemia.

Along with initiatives to understand the pathophysiology of stroke in detail and to identify neuroprotective targets, cell-stabilizing elements have gained increasing attention. Although cell culture experiments have indicated that tricellulin, α-catenin and microfibrillar-associated protein 5 (MFAP5) contribute to cellular integrity, these elements have not yet been investigated in the ischemic brain. Applying immunofluorescence labeling, this study explored tricellulin, MFAP5 and α-catenin in non-ischemic and ischemic brain areas of mice (24, 4 h of ischemia) and rats (4 h of ischemia), along with collagen IV and fibronectin as vascular and extracellular matrix constituents and microtubule-associated protein 2 (MAP2) and neurofilament light chain (NF-L) as cytoskeletal elements. Immunosignals of tricellulin and notably MFAP5 partially appeared in a fiber-like pattern, and α-catenin appeared more in a dotted pattern. Regional associations with vascular and extracellular constituents were found for tricellulin and α-catenin, particularly in ischemic areas. Due to ischemia, signals of tricellulin, MFAP5 and α-catenin decreased concomitantly with MAP2 and NF-L, whereby MFAP5 provided the most sensitive reaction. For the first time, this study demonstrated ischemia-related alterations in tricellulin, MFAP5 and α-catenin along with the vasculature, extracellular matrix and cytoskeleton. Confirmatory studies are needed, also exploring their role in cellular integrity and the potential for neuroprotective approaches in stroke.

Explosion limit of hydrogen/oxygen mixture with water vapor addition

The explosion limits of H2/O2/H2O mixtures with different equivalence ratios are studied. It is shown that the explosion limit of the H2/O2/H2O mixture exhibits the similar Z-shape as that of the H2/O2 explosion limit. As the H2O mole fraction increases, both the first and second limits move towards higher temperatures. Temperature sensitivity analysis and reaction pathway analysis indicate that the third-body reaction related to H2O and the wall destruction of H/O are responsible for the first limit shift to higher temperatures. The second limit moves to higher temperatures due to the enhanced chain termination reactions related to H and HO2, as well as the wall destruction of H, which simultaneously weakens the pathway for the production of O/OH. However, the third limit moves towards lower temperatures when the H2O mole fraction is 0.1–0.3, and then towards higher temperatures when it is greater than 0.3. The reaction path analysis indicate that the addition of H2O promotes the generation of OH. The physical and chemical effects caused by H2O are also studied. The results show that the inert H2O, which does not participate any reactions, causes the first and third limits towards higher temperatures, while the second limit move to lower temperatures. The physical effects and chemical effects caused by H2O result in the non-monotonic movement of the third limit. Compared with above stoichiometric conditions, the first and second limits of the lean mixtures are at lower temperature, whereas the third limit at higher temperatures. The rich mixtures exhibit opposite tendencies.

Clinical Evaluation of Polymerase Chain Reaction Coupled with Quantum Dot Fluorescence Analysis for Diagnosis of Candida Infection in Vulvovaginal Candidiasis Practice.

Time-consuming culture methods and wet-mount microscopy (WMM) with low sensitivity have difficulties in diagnosing Vulvovaginal candidiasis (VVC). Rapid and highly sensitive polymerase chain reaction coupled with quantum dot fluorescence analysis (PCR-QDFA) for the diagnosis of VVC has not been reported to date. This study was the first to evaluate the performance of PCR-QDFA for diagnosis of Candida strains in the leukorrhea samples from patients with suspected VVC. Leukorrhea samples from all visited patients were taken from the vagina using vaginal swabs by clinicians. We evaluated patients admitted with suspected VVC who completed WMM for diagnosis and reported the diagnostic effectiveness of PCR-QDFA and Candida culture (gold standard) when testing leucorrhea samples. A total of 720 leukorrhea samples from 387 VVC-positive patients and 333 VVC-negative patients were included in this study. Of the 387 leukorrhea samples from the VVC-positive patients, 391 Candida strains were identified by culture. 99.23% (388/391) Candida strains were included in the PCR-QDFA list. The 388 Candida strains belonged to four different species of Candida, including C. albicans (n = 273, 70.36%), C. glabrata (n = 85, 21.91%), C. tropicalis (n = 16, 4.12%), and C. krusei (n = 14, 3.61%). PCR-QDFA diagnosed Candida strains in 340/384 (88.54%) of the leucorrhea samples with Candida strains infection. The sensitivity of PCR-QDFA for C. albicans, C. glabrata, C. tropicalis, and C. krusei was 89.01%, 85.88%, 81.25% and 92.86%, respectively. The specificity of PCR-QDFA for C. albicans, C. glabrata, C. tropicalis and C. krusei was 93.69%, 99.37%, 99.71%, and 99.57%, respectively. The highly sensitive and specific PCR-QDFA technique can be exploited as a rapid (approximately 4 h) diagnostic tool for common Candida strains of leucorrhea samples from patients with suspected VVC.

Detection of resistance mutations in patients with anaplastic lymphoma kinase-rearranged lung cancer through liquid biopsy.

Tyrosine kinase inhibitors (TKIs) significantly improve clinical outcomes in patients with non-small cell lung cancer due to anaplastic lymphoma kinase (ALK) gene rearrangement. However, the rate of relapse with TKIs is high owing to the development of resistance mutations during treatment. Repeated biopsies during disease progression are crucial for elucidating the molecular mechanisms underlying the development of resistance to ALK inhibitors. Analysis of cell-free DNA (cfDNA) obtained from plasma is a novel approach for tumor genotyping. In this mixed prospective and retrospective observational cohort study, we investigated the clinical feasibility of continuous quantitative monitoring of ALK-acquired mutations in plasma obtained from patients with ALK+ non-small cell lung cancer by using a highly sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay. We enrolled nine patients, including three treatment-naïve patients recently diagnosed with ALK+ non-small cell lung cancer via tissue biopsy and expected to receive ALK TKIs and six patients already receiving ALK TKIs. Plasma samples were collected from these patients every 3 months. cfDNA was extracted from 66 samples during the study period, and 10 ALK mutations were simultaneously evaluated. The numbers of samples showing the G1202R, C1156Y, G1269A, F1174L, T1151ins, and I1171T mutations were 32, 16, 5, 4, 1, and 1, respectively. The L1196M, L1152R, V1180L, and S1206Y mutations were not detected. Correlation analyses between progression-free survival and the time from treatment initiation (or treatment modification) to the detection of resistance mutations revealed that although resistance mutations may occur before a drug change becomes necessary, there is a duration during which the disease does not progress. Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.

Fine-structure sensitive deep learning framework for predicting catalytic properties with high precision

The fine structure of a surface considerably affects its catalytic performance in structurally sensitive reactions. High-throughput (HT) screening and machine learning (ML) are considered efficient for exploring the hidden rules of impacts. However, no protocol for constructing an interpretable ML framework sensitive to fine structures has been reported thus far. Herein, we developed a data augmented convolutional neural network (CNN)-based ML framework called “global + local” convolutional neural network (GLCNN), which combines “global + local” features. This framework captures original fine structures without the use of complicated encoding methods by transforming the catalytic surfaces and adsorption sites into two-dimensional grids and one-dimensional descriptors, respectively. The GLCNN framework accurately predicted and distinguished the adsorption energies of OH on a set of analogous carbon-based transition-metal single-atom catalysts with a mean absolute error of less than 0.1 eV. Moreover, this model yields the best results among popular models trained on large datasets so far. Unlike conventional CNN and descriptor-based models with one-sided feature extraction, this fine-structure-sensitive ML framework can extract key factors that affect the catalytic performance from both geometric and chemical/electronic features, such as symmetry and coordination elements, through unbiased interpretable analysis. This framework provides a feasible solution for the high-precision HT screening of heterogeneous catalysts with a broad physical and chemical space.

Nutraceuticals Prepared with Specific Strains of Probiotics for Supplementing Gut Microbiota in Hosts Allergic to Certain Foods or Their Additives

Certain nutrients cause discomfort, sensitivity reaction, and an intolerance for certain foods or their ingredients when ingested by some consumers. Food reactions and gut inflammation-related problems are increasing worldwide. The primary form of management would be the avoidance of such foods, followed by treatment of their symptoms. Adopting a nutritional–therapeutic approach and establishing practices for the inclusion of functional foods and nutraceuticals in the diet could improve the ecology of gut microbiota and alleviate inflammation in the GIT. For this purpose, specific species of microorganisms characterized as probiotic strains have been studied to produce functional food and fermented beverage products. Commercially sold, such items are labelled as probiotic products, displaying the name/s of strain/s and the viable numbers of them contained in the portion size of the products. The importance of the growth of probiotic functional foods is that they can be consumed as a source of nutrition and their intake helps in the subsistence and recuperation of friendly gut bacteria. Probiotics have been reported for their role in ameliorating the risk of food reactions. Probiotic administration has been implemented for its role as an auxiliary improvement and for the prevention of food sensitivities common among pediatric patients. Probiotic products based on non-dairy substrates have potential as nutraceuticals for lactose intolerant consumers who are allergic to dairy milk products. Therefore, the aim of this article is to review GRAS microbial species characterized as probiotics up to the level of their specific strain’s name and/or number. These have been used to produce nutraceuticals that are sources of beneficial bacteria for easing discomfort and allergic reactions by maintaining an inflammation-free gut.

Aedes aegypti salivary gland extract alleviates acute itching by blocking TRPA1 channels.

Aedes aegypti (Ae. aegypti) saliva induces a variety of anti-inflammatory and immunomodulatory activities. Interestingly, although it is known that mosquito bites cause allergic reactions in sensitised hosts, the primary exposure of humans to Ae. aegypti does not evoke significant itching. Whether active components in the saliva of Ae. aegypti can counteract the normal itch reaction to injury produced by a histaminergic or non-histaminergic pathway in vertebrate hosts is unknown. This study investigated the effects of Ae. aegypti mosquito salivary gland extract (SGE) on sensitive reactions such as itching and associated skin inflammation. Acute pruritus and plasma extravasation were induced in mice by the intradermal injection of either compound 48/80 (C48/80), the Mas-related G protein-coupled receptor (Mrgpr) agonist chloroquine (CQ), or the transient receptor potential ankyrin 1 (TRPA1) agonist allyl isothiocyanate (AITC). The i.d. co-injection of Ae. aegypti SGE inhibited itching, plasma extravasation, and neutrophil influx evoked by C48/80, but it did not significantly affect mast cell degranulation in situ or in vitro. Additionally, SGE partially reduced CQ- and AITC-induced pruritus in vivo, suggesting that SGE affects pruriceptive nerve firing independently of the histaminergic pathway. Activation of TRPA1 significantly increased intracellular Ca2+ in TRPA-1-transfected HEK293t lineage, which was attenuated by SGE addition. We showed for the first time that Ae. aegypti SGE exerts anti-pruriceptive effects, which are partially regulated by the histamine-independent itch TRPA1 pathway. Thus, SGE may possess bioactive molecules with therapeutic potential for treating nonhistaminergic itch.

The epigenetic regulator Set9 harmonizes fungal development, secondary metabolism, and colonization capacity of Aspergillus flavus

As a widely distributed food-borne pathogenic fungus, Aspergillus flavus and its secondary metabolites, mainly aflatoxin B1 (AFB1), pose a great danger to humans. It is urgent to reveal the complex regulatory network of toxigenic and virulence of this fungus. The bio-function of Set9, a SET-domain-containing histone methyltransferase, is still unknown in A. flavus. By genetic engineering means, this study revealed that, through catalyzing H4K20me2 and -me3, Set9 is involved in fungal growth, reproduction, and mycotoxin production via the orthodox regulation pathway, and regulates fungal colonization on crop kernels through adjusting fungal sensitivity reactions to oxidation stress and cell wall integrity stress. Further domain deletion and point mutation inferred that the SET domain is the core element in catalyzing H4K20 methylation, and D200 site of the domain is the key amino acid in the active center of the methyltransferase. Combined with RNA-seq analysis, this study revealed that Set9 regulates the aflatoxin gene cluster by the AflR-like protein (ALP), other than traditional AflR. This study revealed the epigenetic regulation mechanism of fungal morphogenesis, secondary metabolism, and pathogenicity of A. flavus mediated by the H4K20-methyltransferase Set9, which might provide a potential new target for early prevention of contamination of A. flavus and its deadly mycotoxins.

Experimental and chemical kinetic modeling study of high-temperature oxidation of diisopropyl methylphosphonate (DIMP) - A sarin simulant

Chemical warfare (CW) agent simulants are used in laboratory experiments to study the combustion characteristics of CW agents due to their high toxicity. A crucial CW agent simulant with a chemical structure similar to the deadly nerve agent Sarin (GB) is diisopropyl methylphosphonate (DIMP), an organophosphate compound (OPC). In this study, the high-temperature oxidation of DIMP is investigated in a shock tube at temperatures between 1440 K and 1710 K and a pressure of 1–2 atm. The carbon monoxide mole fraction time histories near 4.9 µm were obtained using laser absorption spectroscopy. The rate parameters for DIMP's H-abstraction reactions with O, and OH radicals were determined using molecular simulations. The rates of reactions involving smaller phosphorous species were also calculated at the CBS-QB3 level. These reactions along with the isopropanol sub-mechanism from the literature were added to the LLNL model to obtain an improved chemical kinetic mechanism for DIMP. Since isopropanol was a major intermediate in DIMP decomposition, validations were conducted with CO time histories during the oxidation of isopropanol. The new model predicted CO during isopropanol oxidation reasonably well. Both the LLNL model and the model developed in this work could predict CO time histories during DIMP oxidation satisfactorily. To comprehend the CO formation pathways and sensitive reactions during DIMP oxidation, reaction path analysis and sensitivity analysis were also carried out. The reaction mechanism developed here will help in the design, development, and optimization of efficient, effective and secure CW destruction techniques.

A specific and sensitive droplet digital polymerase chain reaction assay for the detection of tilapia lake virus in fish tissue and environmental samples.

Tilapia lake virus (TiLV) causes high mortality in farmed and wild tilapia in various countries. We developed a highly specific and sensitive droplet digital polymerase chain reaction (ddPCR) assay to detect and quantify TiLV. The ddPCR assay could detect the virus at a lower threshold than the reverse transcription-quantitative polymerase reaction (RT-qPCR) method, and the sensitivity of the ddPCR assay was 10-fold higher. The diagnostic sensitivity and specificity of the ddPCR assay were 100% and did not cross-react with tilapia tissues infected with Tilapia parvovirus, Infectious spleen and kidney necrosis virus, Aeromonas hydrophila, Streptococcus agalactiae, S. iniae and Francisella noatunensis. The assay reproducibility was demonstrated by a high correlation coefficient of 0.998, and the inter-assay coefficients of variability indicated that the ddPCR assay exhibited low variability within and between measurements. The detection limit of the TiLV ddPCR assay was 100 fg cDNA, which is equal to 3.3 copies of TiLV. Furthermore, the ddPCR assay could detect TiLV in mucus, water and infected tissue samples and the lowest copy number of TiLV detected in water samples by the ddPCR assay was 7.9 ± 0.99 copies/reaction The results of the clinical samples tested for TiLV revealed that the ddPCR assay had a relatively higher detection rate than the RT-qPCR method. Overall, the ddPCR method offers a highly promising approach for the absolute quantification of TiLV in carrier fish and samples from the environment with low viral concentrations.

Selective control of donor-acceptor Stenhouse adduct populations with non-selective stimuli

Selective control of donor-acceptor Stenhouse adduct populations with non-selective stimuli

Relationship between sensory processing sensitivity (SPS) and empathic reaction for pain from psychophysiological perspective

Relationship between sensory processing sensitivity (SPS) and empathic reaction for pain from psychophysiological perspective

Safety of UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food pursuant to Regulation (EU) 2015/2283.

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on UV-treated powder of whole yellow mealworm (Tenebrio molitor larva) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The term yellow mealworm refers to the larval form of the insect species T. molitor. The NF is the UV-treated powder of the whole, thermally dried yellow mealworm. The NF consists mainly of crude protein, fat, digestible carbohydrates and fibre (chitin). The Panel notes that the levels of contaminants in the NF highly depend on the occurrence levels of these substances in the insect feed. The Panel notes furthermore that there are no safety concerns regarding the stability of the NF if the NF complies with the proposed specification limits during its entire shelf life. The NF has a high protein content, although the true protein content in the NF is overestimated when using the nitrogen-to-protein conversion factor of 6.25, due to the presence of non-protein nitrogen. The applicant proposed to use the NF as an ingredient in various food products, such as bakery products, pasta, compotes of fruit/vegetables and cheese. The target population is the general population. The Panel notes that considering the composition of the NF, the proposed conditions of use and that the NF will not be the sole source of dietary protein, the consumption of the NF is not nutritionally disadvantageous. Despite the UV treatment, the Panel notes that the NF is not a significant dietary contributor of vitamin D3. The submitted toxicity studies from the literature did not raise safety concerns. The Panel considers that the consumption of the NF may induce primary sensitisation and allergic reactions to yellow mealworm proteins and may cause allergic reactions in subjects with allergies to crustaceans and dust mites. Additionally, allergens from the feed may end up in the NF. With the exception of possible allergenicity, the Panel concludes that the NF is safe under the proposed uses and use levels.

Structure sensitivity reaction of chloroform hydrodechlorination to light olefins using Pd catalysts supported on carbon nanotubes and carbon nanofibers

The upgrading of wasted chloroform in hydrodechlorination for the production of olefins such as ethylene and propylene is studied by employing four catalysts (PdCl/CNT, PdCl/CNF, PdN/CNT, and PdN/CNF) prepared by different precursors (PdCl2 and Pd(NO3)2) supported on carbon nanotubes (CNT) or carbon nanofibers (CNF). TEM and EXAFS-XANES results confirm that Pd nanoparticle size increases in the order: PdCl/CNT < PdCl/CNF ∼ PdN/CNT < PdN/CNF, descending the electron density of Pd nanoparticles in the same order. It illustrates that PdCl-based catalysts show donation of electrons from support to Pd nanoparticles, which is not observed in PdN-based catalysts. Moreover, this effect is more evident in CNT.The smallest and well-dispersed Pd nanoparticles (NPs) on PdCl/CNT with high electron density favor an excellent and stable activity and a remarkable selectivity to olefins. In contrast, the other three catalysts show lower selectivity to olefins and lower activities which suffer strong deactivation due to the formation of Pd carbides on their larger Pd nanoparticles with lower electron density, compared to PdCl/CNT.

Ceramic Open Cell Foams Featuring Plasmonic Hybrid Metal Nanoparticles for In Situ SERS Monitoring of Catalytic Reactions

AbstractThis work presents porous zirconia‐toughened alumina ceramics functionalized with Au@Pd/Au@Pt core–shell nanoparticle (NP) for in situ monitoring of catalytic reactions via surface‐enhanced Raman scattering (SERS) which is augmented by the open cell foam structure of the ceramic support. In this respect, the porous ceramic enables efficient light trapping and propagation onto the coated surface, which provides good accessibility of the catalyst, while the core–shell particles are equipped with a catalytically active shell and a plasmonic core which enables SERS sensing. The metallic hybrid core–shell NPs are synthesized by the Au‐seed mediated method and colloidally deposited onto the open porous ceramic matrix prepared via the polymer replica method. The Au@Pt NP functionalized porous ceramic show a Raman enhancement factor up to 106, which is significantly higher than that of non‐porous samples. In situ reaction monitoring via SERS is demonstrated by the Pt‐catalyzed reduction of 4‐nitrothiophenol to 4‐aminothiophenol, showing high specificity for analysis of reactants and products. This multifunctional material concept featuring ceramics‐augmented SERS and catalytic activity could be extended beyond real‐time, sensitive reaction monitoring toward high temperature reactions, photothermal catalysis, bioprocessing and ‐sensing, green energy conversion, and related applications.